Dental prosthesis with a valve and vacuum chamber

ABSTRACT

A DENTAL PROSTHESIS WITH A VALVE AND VACUUM CHAMBER IS CHARACTERISED IN THAT THE VALVE IS MADE OF RUST-PROOF MATERIAL AND HAS A RIGID OUTER MEMBER AND A MOVABLE ASSEMBLY WITH A STOPPER FOR PREVENTING PENETRATION OF FOREIGN BODIES AND A SEAL FOR MAINTAINING THE VACUUM, THE STOPPER AND THE SEAL BEING APPLIED AGAINST RESPECTIVE SEATINGS BY SPRING MEANS AND THAT THE VACUUM CHAMBER IS OF SMALLER CROSS-SECTION IN THE PORTIONS THEREOF LYING WITHIN THE EXTENSION OF THE INCISOR AND CANINE TEETH THAN IT IS IN THE PORTIONS THEREOF LOCATED OPPOSITE THE MOLARS.

19, 9 D. l. GREGOROVIC ETAL 3,555,683

DENTAL PROSTHESIS WITH A VALVE AND VACUUM CHAMBER Filed Oct. 24, 1967 INVENTORS DRAGUTIN IVAN GREGOROVIC GEORGES L.E.R.FEROUMONT BY L ATTORNEYS United States Patent Oflice 3,555,683 DENTAL PROSTHESIS WITH A'VALVE AND VACUUM CHAMBER Dragutin Ivan Gregorovic, 1 Quai -Marcellis, Liege, Belgium, and Georges L. E. R. Feroumont, 58 Rue Xhavee, Mons-lez-Liege, Belgium 7 Filed Oct. 24, 1967, Ser. No. 677,652 Claims priority, application lgelgium, Oct. 26, 1966,

Int. Cl. A 61c 13/24 US. Cl. 32-3 1 Claim ABSTRACT OF THE DISCLOSURE It is known that the holding of artificial dentures in position, particularly upper artificial teeth, has been the subject of many proposals based on various expedients such as adhesive powders or pastes, suction between the denture and gums, and so forth.

The hitherto-known solutions have various drawbacks. In particular, there may be mention the often disagreeable taste of pastes and powders, the insufficient grip which does not enable the wearer to chew relatively hard foods such as meat, crusts of bread, certain fruits and vegetables and the embarrassment arising from the wearing of the prosthesis.

One of the best solutions resides in a denture having a longitudinal vacuum chamber provided between its base and the gums, a chamber in which the wearer creates a slight vacuum by aspirating at the time of placing the denture in position. The air is drawn in by suction through a small valve incorporated in the prosthesis and which is intended to maintain the vacuum. A valve of this type is, for example, described in German Pat. No. 1,793,818 granted to one of the applicants for the present patent. However, this valve, like the known valves, is not altogether satisfactory. It does not maintain the necessary tightness and is not very reliable in operation because, during mastication, it allows food particles to penetrate it and impede is functioning, even attacking the delicate elements of which it is constituted. Furthermore, the vacuum chamber has a constant cross-section so that the vacuum effect is either too weak in the extensions of the molds or too strong in the extensions of the canines and incisors. In the first case, the prosthesis is not sufficiently well-held and, in the second, it affects and irritates the gum.

The device proposed by the invention offers an improved valve which does not exhibit the above-mentioned disadvantages of the known valves and vacuum chambers.

Another drawback of known valves resides in the fact that they are placed in the prosthesis after the synthetic resin forming the prosthesis has set (polymerisation), so that they feel uncomfortable and not very safe. Moreover, deformation of the surround frequently occurs and functioning is then faulty.

According to the invention, a dental prosthesis with a valve and vacuum chamber, adapted to be held by a vacuum, is characterised in that the valve, all-the elements of which are made from rustproof materials, has a rigid outer surround and a movable assembly compris- Patented Jan. 19, 1971 ing a stopper for preventing penetration of foreign bodies and a seal for maintenance of the vacuum, said stopper and seal being applied against respective seatings by spring means, and in that the vacuum chamber is of smaller cross-section at right-angles to the incisor and canine teeth than it is in its portions which are situated opposite to the molars. f

Also according to the invention, a method of producing a valve-carrying dental prosthesis having the construction set forth in the last preceding paragraph is characterised by the steps of: inserting the valve, made airtight by two covers, in a provisional mount of readily-meltable material, for example wax, so that one of the said covers, which is a temporary cover, projects from the mould; casting the said mould in removable settable material for example plaster; melting and removing the aforesaid readily-meltable material, placing in position a plate adapted for preparation of the vacuum chamber; introducing and heattreating the material of which the final prosthesis is to consist, said introduced material coating the valve; and removing the aforesaid settable material, the plate, and the temporary cover, and aperturing the other of the aforesaid two covers.

Further, according to the invention, a dental prosthesis, with a valve and vacuum chamber, adapted to be held by a vacuum, is characterised in that the valve, all the elements of which are made from rustproof materials, has a rigid annular outer surround, a gingival inner cover pierceable to provide a small central perforation, an outer cap with a large central perforation and a plane annular inwardly-directed edge, a sleeve, of which the outer lateral face is applied against an inner lateral face of the cover and of the cap, while its bottom has a large central perforation with inwardly returned edges, a movable assembly consisting of a stopper, a head of which rests on the inwardly-directed edge of the outer cap and a body of which is forced into a bush of L-shaped cross-section, the collar of which bush bears on a pressure plate applied to a seal resting on the returned edge of the central perforation of the sleeve, a spring surrounding the bush, hearing against the inwardly-directed edge of the cap and against the collarof the bush, and a temporary cover with a central cup and an edge of greater diameter gripping the upper part of the cap, and in that the vacuum chamber is of smaller cross-section at right-angles to the incisor and canine teeth than it is in its portions which are situated opposite the molars.

A prothesis, with a valve and vacuum chamber, constructed in accordance with the invention, and a plate which enables the vacuum chamber to be formed, are shown, by way of example only, in the accompanying drawings, in which:

FIG. 1 is a cross-section through the valve;

FIG. 2 is, on asjmaller scale, a view of the prosthesis showing the valve in position and the vacuum chamber;

FIG. 3 is a cross-section taken along the line III-III of FIG. 2;

FIG. 4 is a similar view to FIG. 3, but at the time of positioning the valve in a provisional wax prothesis, and

FIG. 5 is a plan view of the plate for the vacuum chamber.

Referring to the drawings, the valve comprises an annular surround 1 of rustproof metal extending upwardly to a first temporary cover 2, likewise of rustproof metal. These two elements are calculated so as to withstand, without appreciable deformation, the pressures of moulding the synthetic material in which they are at least partially coated. The bottom part of the valve is formed by a second cover 3 of rustproof metal introduced into the surround 1, said cover being a tight frictional fit in said surround 1. In its centre, the cover 3 has an outwardly projecting portion 4. The top part of the valve consists of rustproof metal cap 5, which is inserted into, and fits tightly in, the surround 1, this cap 5 having a peripheral returned edge which bears on the underside of a shouldered edge of the cover 2, and said cap 5 having a set-down centre which, at 6, has a central bore. The inwardly-directed edge 7 of the cap 5 is perfectly plane. A sleeve 8, of J-shaped cross-section, is disposed between the cover 3 and the cap 5, its vertical portion being applied against lateral surfaces of the cover and of the cap. This sleeve is likewise made from rustproof metal. Between an inturned and perforated bottom of the shell and the bottom of the cover 3 is a rustproof metal plate 9. The moving assembly of the valve consists of the following elements: a seal of ductile or plastic material, such as a gold leaf, synthetic material, advantageously Teflon, or possibly a mercurial mass, bearing on a seating 11, constituted by the inner returned edge of the sleeve 8; a rustproof metal pressure plate 12 applied on the opposite face of the seal 10; a bush 13 of L-shaped cross-section, made from rustproof metal, and disposed on the pressure plate 12; a spring 14 surrounding the body of the bush 13 and hearing at one end on the collar of the bush 13 and at the other end against the underside of the edge 7, the spring 14 being made from rustproof metal such as gold, platinum or stainless steel; and finally, a T-shaped stopper 15 having its body forced into the bush 13, and its head is applied to the seating constituted by the top face of the edge 7. This stopper is likewise made from rustproof metal. The various rustproof metal elements of which the valve is constituted are advantageously made from 18/8 steel.

The vacuum chamber is formed in known manner by the insertion of a plate into the synthetic resin, before heat treatment. The plate shown, constructed however in conformity with the invention, had, in plan view, two terminal portions 16 and a narrower middle portion 17. It is made from any appropriate metal, preferably flexible, such as aluminium or tin.

Positioning of the valve and creation of the vacuum chamber take place as follows: the valve is inserted into a provisional wax mould of the prosthesis, which already has virtually its final shape; and the temporary cover 2 projects at the inner face of the mould (FIG. 4). The mould is then cast in plaster P in which the cover 2 is coated and rigidly maintained. In known manner, the wax is then melted and removed, the plate adapted for preparation of the vacuum chamber is placed in position and, in known manner, the resin from which the final prosthesis is to consist, is introduced. During this operation,

the valve remains perfectly in position, being anchored by its cover 2 which is shrunk into the plaster. It is protected against the effects of the heavy pressure needed by the strength of the annular surround 1 and, partially, the cover 2. After polymerisation of the resin, the plaster mould is in known manner removed, together with the plate, the impression of which constitutes the vacuum chamber. The cover 2 is then removed and the cover 3 is pierced, for example by the tip of the projection 4 being ground away, or by drilling, hence the necessity for the seal protecting plate 9.

The prosthesis is then ready for use, possibly after possible conventional adjustment.

The functioning of the valve is easily understood: When the prosthesis is applied to the gum G, the wearer exerts a slight suction effect, the movable assembly rises and allows the passage of air which is contained in the vacuum chamber. When the suction effect steps, the spring 14 returns the seal 10 to its seating 11 on the sleeve 8 and the stopper 15 to its seating which is formed by edge 7. A tight seal is thus ensured both against accidental reentry of air into the vacuum chamber and the possible entry of food matter into the valve.

In view of the fact that the valve is made entirely of rustproof materials and since the penetration therein of foreign bodies is not possible, it will retain its initial qualities indefinitely. The stress of application on the gums is correct at all points.

We claim:

1. A method of producing in a mould a valve-carrying dental prosthesis comprising inserting in a temporary mount of readily-meltable material an air-tight valve having a housing with a breakable seal and a temporary cover in such manner that said temporary cover projects from the mould; casting a removable settable material in said mould; melting and removing the aforesaid readily-meltable material; placing in position a plate adapted for preparation of a vacuum chamber; introducing and heat-treating the material of which the final prosthesis is to consist to envelop the valve; removing said settable material together with the plate and said temporary valve cover, and breaking said housing seal.

References Cited UNITED STATES PATENTS 5/1916 Linares 323 8/1959 Kopec et a1. 323 

